manifested than in a recent instance in Prussia. In order to get rid of a large rock, the expense of removing which; by ordinary means, would havẻ been enormous, a deep hole was bored in it, into which was fixed a bar of iron, 28 feet high, for the purpose of attracting lightning. The experiment was successful. On the first thunder-storm, the rock was shattered into fragments, which, of course, were easily carried away.

Colossal Status of Shakspeare. Dr. Carpue lately at the Western Literary Institution, Leices ter-square, stated to the audience that he had an important communication to make on the subject of a statue to Shakspeare, the largest statue ever erected to an individual. Thie King had consented to be the patron, and the Queen the patroness of this plan. The statue to be raised on an elevation 200 feet above the level of the Thames. The pedes. tal to be 60 feet, and the statue 80 feet high. It was also projected that there should be a staircase by which the curious might ascend to the crown of Shakspeare's head; that there should be built near the statue a house, a fac-simile of that in which it is assumed Shakspeare was born, for the residence of the person who should be engaged to show the statue; and that such residence should be allotted to a female descendant of a sister of Shakspeare how alive, but who is in very humble circumstances; and who should also derive any benefit that might accrue from showing the statue. He further mentioned, that the expense would be 20,000., to be raised by subscription; but that no one was to subscribe more than one guinea. For such an object, and that was to be so productive of immediate benefit, he doubted not that there would soon be an adequate amount of subscriptions. The communication, after surprise had somewhat subsided, was greeted with very enthusiastic applause. The Doctor did not say how the descendant of the Shakspeare family was in the interim to be taken care of, nor did he mention when the projectors and caleulators expected that his colossal statue might be completed. -Morning Herald.

Improved Thatching -The Somersetshire mode of thatching is preferable to all others. It consists in using unbruised straw, provincially called reed, instead of braised straw with the ears on it. The practice of Devon, Dorset, and Somerset, in this respect, is an example to all England, which we are surprised has not been more generally followed, as it lasts nearly a long again as common straw, and does not offer the temptation arising froin grains of imperfectly thrashed corn, which induce mice and birds to infest the dwelling and make holes in the thatch. The mode of preparing the straw is simply to take, a sheaf of wheat and to place it in a reed-press, made of two pieces of tim ber ten feet long, put on a stool, and having women to lay hold of the ears of corn, who draw out the straw and cut off the caps, and then bind up the sheaf for use. In this process women are usefully employed in wet weather, and the corn is much more easily thrashed when in short ears than when encumbered with the straw. The thatching work, done with the reed will last ten years longer than that done with the common straw, and as to the appearance there is no comparison; one is an elegant neat covering, and the other a slovenly ragged one. Many gentlenen possessing fancy cottages and rural habitations have been so struck with the neat and picturesque app arance of the enttages in the three Western counties, as to have sent for persons to prepare reed for them in the counties where their dwellings are situate.-Farmer's Magazine.

Another First" Inventor of Steam Boats in America.-A writer in the Philadelphia United States Gazette claims for Rumsey, of Virginia, the honour of first propelling boats by steam in this country. It was many years before Fulton, and

Rumsey was considered a wild enthusiast. With the assistance, however, of a drunken blacksmith at Shepherdstown, he constructed a boat which went up the Potomac against the current at the rate of half a mile the hour. The Legislature of Virginia granted him soine privileges, it is said, which his poverty prevented him from embracing. He afterwards went to England, where he was pa tronised, but died suddenly, leaving his family in indigence the usual melancholy fate of those who have enriched the world with their genius. But as to the matter of priority in the great invention, alluded to, we believe it is pretty well ascertained that the first experiment in this country which bad any thing like the merit of success, was by Fitel, on the Delaware river. The periodicals of the time contain a sketch of the boat, and an account of the experiment. Lieutenant Slideli, however, in his excellent work on Spain, found, in the Archives of Barcelona, authentic evidence that experiments in steam-navigation were successfully attempted in that harbour several centuries since. To the indolent and voluptuous Spaniard, therefore, and nei ther to learned and enlightened England or France, we are indebted for the first conceptions of this inmortal invention. (!)-New York Evening Star.

Beetroot Sugar.-A refinery of sugar from the beet-root is being erected at Thames Bank, Chel sea, which it is expected will be in operation in about six weeks. In the vicinity of the metropolis, during the past summer, a great many acres of land have been put into cultivation with the rootat Wandsworth and other places. The machinery will be principally on the plans of the vacuum pans, and a pure refined sugar will be produced from the juice by the first process of evaporation, after it has simply undergone the process of discolorisation. Another part of the premises is appropriated to the manufactory of coarse brown paper from the refuse, in which it is extensively used in France. In case the government do not interfere, and, by rendering the product exciseable, retard or prohibit its ma nufacture, several individuals have it in contemplation to establish refineries in different parts of the kingdom for purifying sugar, which may be produced in agricultural districts for domestic or individual use. A refinery has lately been established at Belfast, in the vicinity of which town upwards of 200 aeres of land have been put in cultivation with the beet root for the manufacture of sugar.

The publication of the Supplement to Vol. xxv. is unavoidably postponed until the 1st of December:

British and Foreign Patents takenout with economy and despatch; Specifications, Dis. claimers, and Amendments, prepared or revised; Caveats entered; and generally every Branch of Patent Business promptly transacted.

A complete list of Patents from the earliest period (15 Car. II. 1675,) to the present time may be examined. Fee 2s. 6d.; Clients, gratis.

Patent Agency Office,

Peterborough-court, Fleet-street.

LONDON: Published by J. CUNNINGHAM, at the Mechanics' Magazine Office, No. 6, Peterborough-court, between 135 and 136, Fleet-street, Agent for the American Elition, Mr. O. RICH, 12, Red Lion-square. Sold by G. W. M. REYNOLDS, Proprietor of the French, English, and American Library, 55, Rue Neuve, Saint Augustin, Paris.

⚫ CUNNINGHAM and SALMON, Printers, Fleet-street.

PROGRESS OF THE THAMES TUNNEL.

As there now appears to be some likelihood of the completion of Mr. Brunel's

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great bore," we have thought that a statement of its late progress would be interesting to our readers; we, therefore, subjoin the substance of the last Report of the Directors to the hope-sick Proprietors, at a meeting held on the 7th of September last.

The Directors state, that since Midsummer last, "60 feet of the brickwork of the tunnel have been completed, which added to the quantity previously finished, makes a total of 660 feet. By this addition the tunnel is now carried beyond the centre of the river, and is steadily approaching the Wapping shore."

After reminding the Proprietors that the stoppage in 1828, was occasioned by no difficulties of an engineering nature whatever, but solely on account of the original capital of the Subscribers being exhausted," and "that at that time about 599 feet out of 1,300 feet, which is the extreme length of the horizontal roadway and the shaft, were completed for the sum of about 120,000l. only" they proceed with statements more immediately interesting, because they relate to the late progress and present state of the works :

"In their annual Reports of 1835 and 1836, the Directors endeavoured to guard against an undue expectation of progress in the first year, and they did so from three distinct considerations:-They were assured by the Company's engineer, Mr. Brunel, that to remove the old shield and to replace it with a new one would be a work of great expense, of slow progress, and of great danger. The expense, however, is one properly chargeable upon the whole work to be done, and must not be considered as exclusively belonging to that which has been recently completed. They were aware also from experience, that when this hazardous work was effected as it was with unexampled skill and presence of mind, that the knowledge of a vast and complicated machine, and the mode of working it, could only be acquired slowly, and that hence delay in the rate of progress was incidental to the recommencement of the works, and was to be expected for some time afterwards. Added to which, these difficulties were to be encountered under the deep part of the river, where its bed was known to be most unfavourable to the labours of the miners, and most susceptible of the fluctuating influence of the tides. Notwithstanding these difficulties, the tunnel has advanced to

the extent already mentioned; and though they have retarded the progress of the work, yet the miners have acquired both confidence and familiarity in the discharge of their duties and in the management of every part of the shield, and hence it may be fairly anticipated that when the deep part of the river is passed, and where none of the greater difficulties of the undertaking may make speed of less importance than safety to the men and security to the works, a quicker rate of progress will become practicable.

"To enable the Proprietors now to form an opinion of the state of the works, the Directors submit the following details under distinct heads, which are in substance the weekly Reports of Mr. Brunel to the Directors:

"1st. The New Shield has fully answered its purpose, and has enabled the work to proceed through some portions of ground in almost a fluid state. It is greatly superior to the old one. The resistance against which it has to exert its power is computed at about 3000 tons, vertical and lateral pressure; nevertheless, it possesses both facility and precision of movement. Some idea may be formed of the extent of the excavation which it enables the miners to carry on through ground of the consistency previously described, and which it preserves until the brickwork is completed, when it is known that the whole area of the ground is equal to 2000 superficial feet, over the whole of which vents are opened for the infiltration of water both from the river and land-springs, which latter have been found most copious, and sometimes a source of considerable alarm and difficulty. The total area from over which such vents are opened, and through which infiltration takes place, exceeds 75,000 superficial feet.

"2d. The Reservoirs and Drains, lately completed, have under the largest influx of water given facilities to the progress of the miners unknown before. Formerly forty handpumpers, in gangs of twenty each, besides artificers in conjunction with them, were required, who greatly impeded the miners and bricklayers, and who, owing to the adoption of the reservoirs and drains, are now dispensed with.

"3d. State of the Ground.-On the suspension of the late works, a temporary covering of made ground was raised over and around the head of the tunnel, consisting of gravel and clay; but in consequence of the long cessation of the works, the City Authorities ordered this covering to be removed, in order to restore the navigation of the river to its usual state, which was accordingly done. Upon resuming the works, and on examining the ground, the favourable state of it enabled the engineer to proceed for a time without again resorting to the protection which it

afforded; it was, however, thought prudent to obtain from the Lord Mayor permission to resort to this plan when necessary, as a precautionary measure against the great influence of the tides whilst the tunnel is being constructed under deep water. The influx of river-water is discovered by its temperature, as well as by the increased quantity pumped up by the engine, and it is found invariably that a timely resort to this expedient immediately reduces the quantity and brings it under control. The precaution is, therefore, one essential, in the opinion of the engineer, to the security and progress of the works.

"4th. Rate of Progress.-Since the annual meeting, 60 feet of brickwork have been completed which, added to the 10 feet (always occupied by the shield) excavated, makes a total of 670 feet, notwithstanding the difficulties which had to be encountered on the resumption of the works, which have been already alluded to in a former part of this Report. As the tunnel approaches the opposite shore, the difficulties of the undertaking will decrease. The thickening of the crust of earth, or the bed of the river over the head of the miners, will render the more rapid advance of the shield perfectly practicable; and as the works will then be carried on under shallower water, they will be less influenced by the tides.

"In a Report made on the 24th of August to the Directors, Mr. Brunel says, 'Contrasting our present state, however, with almost the whole course of June last, it will be seen that we have gained considerably in every respect. On many occasions in June we were obliged to block up and timber the top boxes, and even to suspend our proceedings until we could approach, as it were, the top polings and probe the ground; but since and from the auxiliary means which I adopted on the 2d of July, and made an application of on that day, not one single instance is recorded of the boxes being blocked up, or of ground breaking in; on the contrary, the ground which could not be worked before, and wherein a pricker entered seven feet ahead, was worked with perfect security. We may anticipate that we shall gradually improve in progress.' The auxiliary means alluded to in the foregoing Report, and which can only be generally described, consist of a system of pinning and isolating a portion of ground, which is then removed without disturbing the contiguous portion from which it is taken, and which has enabled the work of excavation to proceed under the most formidable circumstances. system, combined with a mode now adopted .of at onee conveying away the land-springs and directing their course to the reservoirs, instead of attempting to stop their influx, has enabled the miners to proceed where difficulties have appeared at first almost insuperable.

This

"In Mr. Brunel the Directors continue their unabated confidence, and, in conclusion, whilst they remind the Proprietors that the work is one not yet free from both uncertainty and danger, they still desire to reiterate their opinion, that at no very distant period this great undertaking will, inspite of opposing difficulties, be completed, and a communication made between the shores of one of the deepest parts of the river, where within a small space the trade and navigation of London may almost be said to be concentrated: and that, in all probability, this communication will be made at less than halfthe expense of any communication for similar purposes within the range of the metropolis.

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(Signed) BENJ. HAWES, Chairman. "Sept. 7, 1836."

Our front page engraving illustrates the progress of the works. The dark part of the tunnel is that which is finished. A, the position of the shield on the 7th of September, 1836. The light part, with dotted lines, shows the portion remaining to be done; B B are the low water-marks; C, the Rotherhithe shaft, for the entrance of foot-passengers to the tunnel; the dotted circle shows the more gradually descending roadway for carriages and waggons; D, St. Mary's Church. The part of the tunnel from low water-mark to the shaft on the Wapping side of the river (about 350 feet,) is not shown in the engraving.

THE NEWTONIAN PHILOSOPHY.

Sir, Indisposition has prevented me from sooner fulfilling the promise I made at the conclusion of my last letter.

Mr. Mackintosh objects to Newton's first law of motion, namely, "Every body continues at rest, or in uniform rectilineal motion, unless affected by some mechanical force."

Mr. Mackintosh is not the first who has objected to this law; hundreds of others have done the same, and thousands of pages have been written on the subject -from the days of Toland (one of Newton's bitterest opponents) to the present time. It has been urged, that if we grant the truth of the Copernican and Newtonian description of the planetary mo tion, then we admit there is no such thing as rest, or uniform rectilineal mòtion. Nor has Newton himself any where asserted, that there really exists in nature such a thing as absolute rest, or a continual and uniform rectilineal motion.

Let it be remembered, that he has introduced a limitation in the above law, "unless affected by some mechanical force." The nature of such forces he has duly considered in his immortal "Principles of Natural Philosophy." He migh', perhaps, have been induced to assert the truth of this law, or axiom, or principle, by knowing that the planets have continued for ages, or as far as observations can be traced, without the smallest perceptible diminution of their motions; and if at any point in their orbits the forces that regulate their motions were supposed to be decomposed, that representing the centrifugal force would produce uniform rectilineal motion. But to do away with the idea of uniform rectilineal motion, would be a source leading to continual blunders.

Professor Robinson, after enumerating and answering the objections that have been urged by a certain class of philosophers against the soundness of Newton's first law, thus concludes:

“All these differences of opinion may be completely settled by adhering to the principle, that every change is an effect.' It is a matter of fact that the human mind always considers it as such. Therefore, the law is strictly deduced from our ideas of motion and its causes; for even if it were essential to matter gradually to diminish its motion, and at last come to rest, this would not invalidate the law, because our understanding would consider this diminution as the indication of an essential, or, at least, a universal property of matter. * * * We should ascribe it to a natural retarding force, in the same way as we give this name to the weight of an arrow discharged straight up. wards. The nature of existing matter would be considered as the cause, and we should estimate the law of its action as we have done in the case of gravity; and, as in that case, we should still suppose that were it not for this particular property, the material atom would continue its motion for ever undiminished," &c.

But let Mr. Mackintosh point out any proposition in the Principia depending on this law, and show (if he can) that it is inconsistent with facts deduced from astronomical observations.

Mr. Mackintosh accuses me of attacking the electrical theory with more as perity than appears to him to be needful. He may think so, but I judge otherwise Indeed, I would have acted exactly in the same way had Mr. Mackintosh been my own father, or brother, or son.

I

have paid no small degree of attention to the Newtonian system; and I am free to confess, that the more I study it, the more I become satisfied of its truth. And as I find so many parts of the electrical theory opposed to that of universal gravitation, I think that, as an old correspondent of the Mechanics' Magazine, I would have neglected my duty had I allowed the subject to pass unnoticed; nor had Mr. Mackintosh any right to suppose that such would have been the case.

seen.

Mr. Mackintosh's method of accounting for the diurnal motion of the earth by means of galvanic circles and electrical currents, &c. puts one much in mind of the whirlpools and vortices of Cleanthes and Descartes, and the celestial machinery of Eudoxes and Callippus. These philosophers placed the whole of their celestial mechanism in the heavens, where they had some chance of being Mr. Mackintosh, with more circumspection, has entombed his under the surface of the revolving planet. Now, if we could force ourselves to believe in Mr. Mackintosh's theory, we must admit that the Supreme Architect himself is unacquainted with eternal or perpetual motion, for notwithstanding all the care he has taken to preserve the rotary and revolving motions as long as possible, still both must come to an end, and the "earth cease to revolve upon her axis." Mr. Mackintosh, in fact, tells us, that the rotary motion of the moon has already ceased! (No. 645, p. 233, 234.) It is strange (if true) that none of our astronomers have thought proper to give us any information of this astounding fact; or has Mr. Mackintosh merely made this assertion for the purpose of trying how far he could play upon the credulity of some of his readers (friend Ursa for one)? Or it may be (for I would not wish to deal harshly with him), that he had not duly considered the subject when he made this strange assertion. But be that as it may, let any one contrast this fanci ful part of his (Mr. Mackintosh's) theory with that given by Newton, and let him say which is most probable. Newton requires no complex machinery in des monstrating the rotary and revolving motions; all that he requires is the figure of the planet, and a proper appli cation of gravity, and all this is fully borne out by testing his theory with ancient and modern observations. Thus, for instance, the length of the day has